Merge pull request #942 from permissionlesstech/fix/BCH-01-002-file-storage-dos

fix BCH-01-002: prevent DoS via file storage exhaustion

bitchat/Services/BLE/BLEService.swift

@@ -1155,6 +1155,9 @@ final class BLEService: NSObject {
             return
         }
 
+        // BCH-01-002: Enforce storage quota before saving
+        enforceIncomingFilesQuota(reservingBytes: filePacket.content.count)
+
         let fallbackExt = mime.defaultExtension
         let subdirectory: String
         switch mime.category {
@@ -1390,6 +1393,72 @@ final class BLEService: NSObject {
         }
     }
 
+    // MARK: - Storage Quota Management (BCH-01-002)
+
+    /// Maximum total storage for incoming files (100 MB)
+    private static let incomingFilesQuota: Int64 = 100 * 1024 * 1024
+
+    /// Enforces storage quota for incoming files by deleting oldest files when quota is exceeded.
+    /// Call before saving a new incoming file.
+    private func enforceIncomingFilesQuota(reservingBytes: Int) {
+        do {
+            let base = try applicationFilesDirectory()
+            let incomingDirs = [
+                base.appendingPathComponent("voicenotes/incoming", isDirectory: true),
+                base.appendingPathComponent("images/incoming", isDirectory: true),
+                base.appendingPathComponent("files/incoming", isDirectory: true)
+            ]
+
+            // Gather all incoming files with their sizes and modification dates
+            var allFiles: [(url: URL, size: Int64, modified: Date)] = []
+            let fileManager = FileManager.default
+
+            for dir in incomingDirs {
+                guard fileManager.fileExists(atPath: dir.path) else { continue }
+                guard let contents = try? fileManager.contentsOfDirectory(
+                    at: dir,
+                    includingPropertiesForKeys: [.fileSizeKey, .contentModificationDateKey],
+                    options: [.skipsHiddenFiles]
+                ) else { continue }
+
+                for fileURL in contents {
+                    guard let attrs = try? fileURL.resourceValues(forKeys: [.fileSizeKey, .contentModificationDateKey]),
+                          let size = attrs.fileSize,
+                          let modified = attrs.contentModificationDate else { continue }
+                    allFiles.append((url: fileURL, size: Int64(size), modified: modified))
+                }
+            }
+
+            // Calculate current usage
+            let currentUsage = allFiles.reduce(0) { $0 + $1.size }
+            let targetUsage = Self.incomingFilesQuota - Int64(reservingBytes)
+
+            guard currentUsage > targetUsage else { return }
+
+            // Sort by modification date (oldest first) and delete until under quota
+            let sortedFiles = allFiles.sorted { $0.modified < $1.modified }
+            var freedSpace: Int64 = 0
+            let needToFree = currentUsage - targetUsage
+
+            for file in sortedFiles {
+                guard freedSpace < needToFree else { break }
+                do {
+                    try fileManager.removeItem(at: file.url)
+                    freedSpace += file.size
+                    SecureLogger.debug("🗑️ BCH-01-002: Deleted old incoming file to free space: \(file.url.lastPathComponent)", category: .security)
+                } catch {
+                    SecureLogger.warning("⚠️ Failed to delete old file for quota: \(error)", category: .security)
+                }
+            }
+
+            if freedSpace > 0 {
+                SecureLogger.info("📊 BCH-01-002: Freed \(ByteCountFormatter.string(fromByteCount: freedSpace, countStyle: .file)) to stay within incoming files quota", category: .security)
+            }
+        } catch {
+            SecureLogger.warning("⚠️ Could not enforce storage quota: \(error)", category: .security)
+        }
+    }
+
     private func sendLeave() {
         SecureLogger.debug("👋 Sending leave announcement", category: .session)
         let packet = BitchatPacket(

bitchat/Services/Transport.swift

@@ -58,6 +58,10 @@ protocol Transport: AnyObject {
     // QR verification (optional for transports)
     func sendVerifyChallenge(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
     func sendVerifyResponse(to peerID: PeerID, noiseKeyHex: String, nonceA: Data)
+
+    // Pending file management (BCH-01-002: files held in memory until user accepts)
+    func acceptPendingFile(id: String) -> URL?
+    func declinePendingFile(id: String)
 }
 
 extension Transport {
@@ -70,6 +74,9 @@ extension Transport {
     func sendMessage(_ content: String, mentions: [String], messageID: String, timestamp: Date) {
         sendMessage(content, mentions: mentions)
     }
+
+    func acceptPendingFile(id: String) -> URL? { nil }
+    func declinePendingFile(id: String) {}
 }
 
 protocol TransportPeerEventsDelegate: AnyObject {